Powerhead Speed Controller Question

So I bought two Maxi Jet 600's and just picked up the Sure Flow 1600 Maxi-Jet Upgrade. Holy Crap are these things awesome. Such a great deal for so much flow. It is so much flow for my frag tanks that I am thinking it may be too much. According to the specs of the kit, it is producing 1400gph each. It makes my Koralia 4's look like nothing. Does anyone know if there is a way to hook up a dimmer switch or something to this pump to slow the speed down? Is it even possible to make your own speed controller for powerheads?

A dimmer switch will not work as a speed control on a maxijet. The type of motor used in most of our less expensive pumps rotate at a fixed rate.

You can use an on-off (aka bang-bang) controller / wavemaker, like a Red Sea WaveMaster Pro, but the ambiguity in the startup direction of the pump may physically wear your upgrade out earlier than it would otherwise.

I've never tried this, but it may be an option of sorts. If you restricted the input to the pump, it should move less water. In the case of your maxijet mod, this would require that you block off some of the grating on the intake side of the the propeller. Maybe you could experiment with this using some rubber plumbers tape or something similar.

the maxi jet can not be dimmed or throttled via an electrical method, it just can't happen. I could explain it but it's long, boring, and won't solve anything. The way you can control the amount of water they put out issss ready for this? PVC take your shroud for your newly modded power head to your local home depot or lowes and find the closest fitting piece of pvc pipe (in diameter) that will fit over the shroud, the tighter the fit the better as long as you can get it all the way over the shroud. Cut it to the length of your shroud (the pvc pipe) now comes the hard fun tricky part. You need to slot the pipe the same way the shroud is slotted and once you have that done you can put it back over the shroud and by twisting this second shroud over top of the stock one you can regulate the amount of water it can take in and there by put out allowing you to control the flow

I have a MP40w on my main tank. Its great, but the whole purpose of going with Max-Jet Mods is to cut down on expenses.

the maxi jet can not be dimmed or throttled via an electrical method, it just can't happen. I could explain it but it's long, boring, and won't solve anything. The way you can control the amount of water they put out issss ready for this? PVC take your shroud for your newly modded power head to your local home depot or lowes and find the closest fitting piece of pvc pipe (in diameter) that will fit over the shroud, the tighter the fit the better as long as you can get it all the way over the shroud. Cut it to the length of your shroud (the pvc pipe) now comes the hard fun tricky part. You need to slot the pipe the same way the shroud is slotted and once you have that done you can put it back over the shroud and by twisting this second shroud over top of the stock one you can regulate the amount of water it can take in and there by put out allowing you to control the flow

That is a great idea! I am going to have to try it. Last night I found a dimer switch and hooked it up to the Max-Jet. I now understand why it won't work. So I guess the only real way to cut the flow back is to interfere with the intake.

Even though Jason's idea is very elegant I can see a problem with it. This pumps (with the mod) tend to change direction if the flow is disturbed in any way. I use a couple of them, and they put a ton of flow for the money, but they spin backwards half of the time. I have to put my hand in front of the pump and then it will spin in the right direction. I am afraid that if you limit the intake with the PVC pipe you might have a pump that switches direction constantly. I haven't tried it personally, I will tonight when I get home, but you can test it by covering the shroud with your hand.

Sorry, I have to say it. Here is the better information. You don't want to use a dimmer. They either use a rheostat or a triac. There are several problems with this. One of them being is that you can damage the motor. Restricting the flow isn't a good idea either. The problem is that when you do that, you put extra resistance on the impeller (FYI if this was setup differently, that could damage the motor). Anyway, putting the extra resistance on the impeller could (usually does) damage the impeller. What you want is a variac, but it really isn't cost affective. Trying to modify the speed is going to a pain and not cost effective.

So what are your other choices? Well why is the flow a problem? Is it pushing everything around? If so, you could just diffuse the stream. My guess is that would work well for you. If you have too much turnover or flow, you could go with a wave maker. You could also combine that with the diffusing the stream concept. You could also aim your stream in a way so that it doesn't have a direct flow problem. For instance, you could aim it towards the surface.

Could it be the reason you can not put a dimmer or rheostat on a Maxi-Jet, is due to the fact the motor runs on AC current, now if you had a DC current motor you could achieve this, but a DC motor does not have the same start or run torque as an AC motor.

As for the slip over slot method: That would be a temp fix for a long running problem. Eventually your going to have Coraline growth on those slots and the flow will just reduce even more. If you ask me I would just rather cut some thin plastic strips and custom fit them over a few slots at a time until you feel you have the proper flow restricted. Yes it will take some time but in the end the long hard work will pay off in the end.

75 gallons of bliss grew up and became 120 gallons of pure family fun. Lots of various creatures of interest !!